Gravity-feed napkin dispensers are well known. In this respect there is shown in U.S. Pat. No. 5,100,020 to Petterson et al. a dispenser for serially dispensing products such as paper napkins from a stack. The dispenser apparatus includes a housing having a back wall which is curved and has a radius of curvature generally corresponding to the radius of curvature of the stack.
In U.S. Pat. No. 5,102,007 also to Petterson et al. there is shown an improvement to the '020 patent wherein the dispenser is provided with a blocking member which obstructs the interior of the housing above a stack after the stack has been shortened to a predetermined degree to prevent an upward force against the stack from moving the stack away from its dispensing position. See also U.S. Pat. No. 5,156,293 and U.S. Pat. No. Des. 331,515 to Petterson et al.
The dispenser illustrated in the foregoing patents is configured to receive a stack of single-fold, non-interfolded napkins and supports them inside a gently curving housing having a substantially rectangular cross section which is inclined from a vertical at an angle of approximately 10° at its upper extremity and approximately 25° at its lower extremity. Accordingly, the surfaces of the napkins are substantially horizontal nearer the upper extremity of the dispenser, but are rather more inclined with respect to a horizontal position in the lower portion of the dispenser. When filled, the napkins lie against a face plate which constitutes the lower surface of the dispenser, but a portion of the weight of the stack is borne by the back wall of the dispensing cavity which ameliorates jamming problems which might occur if the entire weight of the stack of napkins were borne by the face plate.
One operating difficulty with this type of dispenser is that when a napkin stack becomes almost completely depleted, there is a tendency for the few remaining napkins in the dispenser to fall back against the rear or back wall rather than lying against the dispensing face plate which has the dispensing aperture formed therein. When the napkins fall back, it makes it difficult for a user to grasp a single napkin and withdraw one through the opening. Accordingly, this drawback can defeat the purpose of the dispenser which is to make it easy for the user to withdraw a single napkin but more difficult to withdraw multiple napkins at the same time. The '007 patent addresses this problem by providing an opening or recess in the back wall of the dispensing cavity spaced perhaps an inch or two above the lower face plate of the dispenser through which a J-shaped blocking arm extends. The arm hingedly mounts on the dispenser such that it can be pivoted so that the hook of the J is able to move through an opening into the interior of the dispenser. A light spring urges the J-shaped locking member away from the back wall of the dispenser and into the dispensing cavity; however, the spring constant is chosen to ensure that the weight of the stack of napkins will be sufficient to urge the blocker arm against the rear surface of the dispensing cavity so that it does not interfere with the gravity feeding of the napkins. While the J-shaped blocking member prevents the last several napkins from falling against the rear wall of the cavity, as it rotates into position a few napkins are often carried upwardly by the vertical stroke portion of the J-shaped blocking member and carried away from the dispensing aperture. Some product thus becomes either pressed against the front wall of the dispenser or is otherwise made inaccessible to a user.